A305353 Expansion of Product_{k>=1} (1 - x^phi(k)), where phi is Euler's totient function.

1, -2, -2, 6, -4, 2, 6, -14, 8, -2, 4, -6, -16, 38, -22, 6, 2, -10, 2, 6, 60, -126, 28, 70, -38, 6, -38, 70, -54, 38, 18, -74, -70, 214, 106, -426, 186, 54, -26, -2, -92, 186, -218, 250, -66, -118, -104, 326, 466, -1258, 500, 258, -254, 250, -368, 486, -342, 198

Offset

0,2

Links

Table of n, a(n) for n=0..57.

Formula

Product_{k>=1} (1 - x^k)^A014197(k).

Mathematica

terms = 58;
S[m_] := S[m] = CoefficientList[Product[1 - x^EulerPhi[k],
     {k, 1, m*terms}] + O[x]^terms, x];
S[m = 1];
S[m++];
While[S[m] != S[m - 1], m++];
S[m] (* Jean-François Alcover, May 12 2022 *)

Crossrefs

Cf. A000010 (phi), A014197, A120963, A280611.

Sequence in context: A138565 A137316 A064851 * A134458 A193819 A356790

Adjacent sequences: A305350 A305351 A305352 * A305354 A305355 A305356

Keyword

sign

Author

Seiichi Manyama, May 31 2018

Status

approved